1. Field of the Invention.
The present invention relates generally to the field of simulations for medical training. More specifically, the present invention discloses a system for training persons to perform minimally invasive surgical procedures.
2. Statement of the Problem.
Surgery of any form is a stressful imposition on a body. With traditional surgery techniques the incision itself imposes additional risk of infection, trauma, and recovery time upon a patient, beyond that imposed by the condition giving rise to need for surgery. Advances in miniaturization of tools and implements, as well as video systems to view the internal landscapes of patients, have given rise to minimally invasive surgical techniques. In this field of surgery, a tiny incision is made in the patient and the surgical implement is inserted into a vein, artery, or space between tissue. Tactile sensation imparted to the surgeon by the implement as it is inserted into the patient and visual display images from x-ray or other systems allowing an internal view of the body are then used to position the implement and complete the necessary task of the operation, be it repair of an organ such as the heart, removal of blocking tissue, the placement of a pacemaker lead, endoscopic surgery or other procedure. Due to the minimally invasive nature of this type of surgery, operations may be performed in a very brief period of time on patients with less than full anesthesia and hospitalization. Given the nature of this type of operating procedure there are a number of special considerations. Failure to properly orient the implement within the patient, or properly recognize the tissue through which the implement is passing, may result in the implement puncturing or rupturing a vein, artery, organ, or other internal tissue structure. Such an accident will almost certainly result in subjecting the patient to immediate emergency invasive surgery, morbidity, and perhaps mortality. To avoid such an accident, the surgeon must properly associate tactile feedback from the implement and imagery from the display showing the location of the implement relative to the patient's internal landscape. As normal pressures in arteries, tracts, veins, and organs as well as the physical movement of breathing and heartbeat cause changes to the internal patient landscape and affect the movement of the implement, it has seemed that the only way for a practitioner to gain the requisite skills and techniques is by experience with live patients. In addition, the internal conditions and landscapes vary from person to person. For example, constrictions and restrictions appear with sufficient regularity to be expected, but precise locations vary with each patient. Accordingly, the tendency is for those physicians already experienced with the procedure to be asked to perform the operation. It is therefore difficult for inexperienced physicians to obtain a desired level of familiarity and competence leading to requisite certifications. Additionally, there are procedures that are performed on less than a constant basis. Without performing the procedure often, the practitioner has no method to maintain the high degree of skill that is obtained only through routine frequent performance. Further, it is not possible to implement new methods, operations, and procedures except on live persons. Accordingly, there is a need for an effective means to simulate real-life operations, provide tactile force feedback and simulate video imagery of the patients internal landscape and the surgical implement as they would appear and move in an actual operation, so as to develop and maintain skill, and implement new techniques.
The components involved in the present invention are in some respects similar to video simulation systems, medical training systems, and minimally invasive surgical training systems that have been developed in the past, including the following:
______________________________________ Inventor Patent No. Issue Date ______________________________________ Kalawsky 5,394,517 February 28, 1995 Cohen 5,113,177 May 12, 1992 Olsen et al. 5,012,342 April 30, 1991 Troxell 4,975,770 December 4, 1990 Welsh et al. 4,970,666 November 13, 1990 Walker et al. 4,954,970 September 4, 1990 Gale 4,952,024 August 28, 1990 Mecklenborg 4,205,224 May 27, 1980 Hon 4,907,973 March 13, 1990 Hon 4,360,345 November 23, 1982 ______________________________________
Kalawsky discloses a computer-controlled integrated real and virtual environment display system having two video cameras matching the simulator user's field of view. Signals from the video cameras are analyzed to determine the presence of predetermined color or intensity. A computer-generated image is then created and positioned within the field of view on the basis of what is or is not perceived to be present in the field of view.
Cohen discloses an apparatus for a display system enabling a pilot in an aircraft to view simultaneously an image of selected display information and a scene external to the aircraft during low visibility conditions. A combined image of the exterior view and display is presented on the pilot's visor.
Olsen et al. disclose a video prioritizer and mixer allowing two or more video sources, such as an in-house data terminal source and a graphics source, to be mixed for display on a single video monitor display.
Troxell discloses a method for enhancing golf green contours for television broadcasts. A grid pattern of intersecting parallel lines is projected over the golf green, recorded, and then broadcast onto a television screen simultaneously with the broadcast of the golf green during play thereon.
Welsh et al. disclose a computerized system for producing highly realistic video images that depict the appearance of a simulated structure in an actual environment, providing for accurate placement and perspective of the structure, allowing renderings of buildings to be viewed in proposed settings prior to actual construction. Measurement of the actual scene is required from the center of view and the camera station point so as to adjust the computer-generated image proportionately.
Walker et al. disclose a system for rapidly generating overlay images by color painting techniques using a host computer with an appropriate graphics-generation operator interface, and for manipulating overlay images with respect to a background image.
Gale discloses a three-dimensional sight and sound reproduction apparatus for individual use. A headset provides visual displays directly before the user's eyes and audio speakers provide sound directly to the user's ears, rendering a user immersed in a three-dimensional virtual reality of sight and sound for enhanced reality and viewing pleasure.
Mecklenborg discloses a binocular viewing technique allowing simulation of objects in close proximity to a flight simulator pilot to be perceived with an enhanced three-dimensional appearance. The images presented to the training individual's left and right eyes are separate and distinct images from respective left and right display systems, which allows the size, shape, and orientation of each image to be separately controlled.
The Hon '345 patent discloses a computer-controlled interactive instruction system for teaching an individual how to administer cardiopulmonary resuscitation. Structured toward comparing a technique being administered to a dummy with standard indicia stored in the computer memory, this system does not propose operator-defined surrogate invasive travel within the subject. Further, this prior art, being structured to specific performances and external responses, does not provide for complete and non-restricted environmental modeling of potentially encounterable conditions.
The Hon '973 patent discloses a computer-controlled interactive instruction system for teaching an individual to perform many types of invasive or semi-invasive procedures. This system incorporates the use of a simulated implement, and a physical model representing, physically and spatially, at least that portion of a patient on which a selected procedure is to be performed. This model is equipped with spaced sensors, constrictors, and other physical characteristics that are used to re-create the physical characteristics of a patient's internal landscape.
3. Solution to the Problem.
None of the prior art references uncovered in the search show a minimally invasive surgical procedure simulator having the structure of the present invention. In particular, the system can be used to control tactile force feedback at any point in the procedure, and dynamically adapt the simulation such that the practicing physician does not become accustomed to encountering the same conditions in the same locations, as would never occur in a real operation. Further, none of the prior art cited above incorporates the realism of both visually displaying and tactilely affecting the implement within the patient as the patients internal landscape is continually changed by the process of breathing and heartbeat.